Toy steam engine



mimi@ E. H. MllTH TOY STEAM ENGINE Original Filed Jan. 26, 1932 BNVENTOFQ Patented Sept. 24, 1935 UNITED STATES traes PATENT OFFICE Application January 26, 193,2, Serial No. 588,940 Renewed January 29, 1935 8 Claims.

. This invention relates totoy steam engines, and particularly to toy steam locomotives. Among the objects of the invention is to combine such steam engines or locomotives with a highly 5 eiiicient, simple and safe electrical heater that will permit the generation of steam in the boilers of such engines or locomotives from the ordinary electric socket and from ordinary electric toy-train rails, while positively preventing the l burning out of the heater and also assuring notice to the user of excessive drop of the water level in the boiler.

The features o-f the invention will be best understood from the following description of an exl emplication thereof, reference being had to the accompanying drawing, wherein Fig. l is a partially diagrammatic elevational View with part in section of a toy steam locomotive embodying the invention;

Fig. 2 is a vertical sectional view of the steam boiler of the toy steam locomotive; and

Fig. 3 is a transverse sectional View of Fig. 2 along lines 3 3.

Toy steam engines and toy steam locomotives awaken much more interest in children, for whose entertainment and instruction they are designed, than electrically driven toy trains. In electrically driven toy trains the driving power is supplied by a little electric motor which, as a rule, is

nothing but a little covered unit, which in itself does not awaken much interest in children. Steam toy engines and steam toy trains on the contrary have a large number of exposed moving engine parts and also emit exhaust steam and display greater activity, so that they raise much more interest in children and young people than locomotives driven by electric motors. Notwithstanding this greater interest of children in steam locomotives, the use of such steam toys is relatively small, because it was found that for practical, efcient and simple generation of steam in such toys it was best to use burners supplied with a liquid fuel, such as alcohol, held in a little tank on the locomotive or engine. Toys with such alcohol burners or the like are a source of serious danger because they lead often to iires or explosions involving a great deal of danger. The unpleasant alcohol vapors that are produced in operating such locomotives are also very objectionable in the home.

Efforts have bee-n made to generate the steam in such toy boilers by electrical heaters supplied from the home lighting system, but as far as I am aware, no practical, successful toy steam engines and locomotives with electrical steam generating heaters have heretofore been made because of the complications and excessive costs of the complicated structures heretofore proposed, the burning out of the heaters when an excess or all of the water in the boiler chamber boiled away, and 5 similar reasons.

The apparatus of my invention overcomes these difculties and enables electric steam generation in boilers oi toy engines, locomotives or the like by extremely simple and inexpensive electric l0 heating means that are rugged and damageroof, do not burn out even if the boiler accidentally boils dry, and which in addition is arranged to warn the users of the toy of excessive fall of the water level in the boiler.

A toy steam locomotive l embodying such electrical steam generation is shown in general outline in Fig. l, the locomotive running on a rail system 2 such as is generally used with electricmotor driven locomotives, the rail system com- 20 prising two outer rails 3 adapted to carry and guide the wheels of the locomotive and a third rail fl, usually disposed in the center between the main rails 3 and insulated therefrom. The outer rails 3 and the third rail 4 are held together 25 by cross rails 5, the third rail 4 being insulated from the cross rails as is usual in electric trains.

Electric energy is applied to the rail system by means of a transformer 6 having a primary winding l adapted to be connected by means of an 30 ordinary plug to a socket of the home lighting system, and a secondary winding 8 which is connected between the outer rails3 and the third rail il to impress a potential thereacross, like in ordinary electric toy trains, The same trans- 35 formation ratio may be used as in ordinary electric toy trains, the secondary winding 8 applying, for instance, to the third rail d a voltage of Z5 volts against the outer rails 3.

The steam boiler and the engine equipment of 40 the locomotive I may be the same as that of the standard toy steam boilers, such locomotives having, as a rule, a steam boiler Il, engines i2 with the usual driving and regulating equipment, pipes for supplying the steam from the 40 boiler Il to the engines I2, and exhaust pipes which discharge the exhaust steam from the engines through the chimney I3 to make it appear as if smoke were issuing from the chimney. These parts are common in all the toy steam locomotives 50 on the market.

In distinction, however, from such ordinary toy steam locomotives, no alcohol burner or the like is provided on the locomotive. Instead, a special electric heater is built in the locomotive to gener- 55 ate steam in the boiler. As seen in Fig. 2, the boiler chamber II has a main cylindrical section I5 closed by a front end-plate I8 and a rear endplate I1 so as to be able to hold steam generating fluid, such as water, and steam under pressure. The level of the water is indicated at IB and may drop down to a considerable extent during operation. Inside this boiler, immersed in the Water, is mounted an electrical heater I9, the heater being in the form of a helix resting lengthwise the bottom of the boiler and insulated from the metallic boiler walls I5 by an insulating barrier or layer 20 which overlies the inner bottom surface of the boiler cylinder. This insulating layer 20 may extend for the full length of the boiler chamber and may suitably be held in place, as by means of clips 2| engaging the edges of the layer. The insulating layer 20 may be made of a strip of mica, porcelain or other insulating material that will prevent short-circuiting of the turns of the heater coil I9 with the conducting walls of the cylinder I5.

The heater coil I9 is made of a relatively rigid resistance wire so that when it is in stretched position on the bottom of the boiler cylinder I5 as shown in Fig. 2, it will stay rigidly in place by merely fixing the forward end 22 of the coil and the rear end 23 of the coil. The front end 22 of the coil is rigidly connected to the bottom of the boiler cylinder I I by threading it through an opening 24 drilled in the bottom of the boiler and an adjacent overlying boss, the several elements being soldered or otherwise hermetically and rigidly joined together so that the coil end 22 is firmly held in place and fixes the position of the forward end of the heater coil I9.

The rear end 23 of the coil is similarly connected in a rigid manner to a metallic lead-out bolt 25, as by soldering, the bolt extending through an opening in the rear wall I1 of the boiler chamber and being rigidly and tightly held therein, insulated from the wall I1, by an insulating bushing 21 and an interfitting collar 28 tightly enclosing the opening so that water and steam will not escape therefrom. The bolt 25 with the bushing and collar are locked in place by means of a washer 29 and a nut l3l) on the outside of the boiler within the cab 3| of the locomotive. A supporting block 33 is suitably mounted in the cab 3I as by means of rivets 34. To this block is secured by means of bolts 35 a spring arm 36 having at its end a contact shoe 31 engaging the third rail and establishing electric connection therewith. The other end of the spring arm has clamped thereto the end of an insulated connecting Wire 38 which in turn has its end clamped to the lead-out bolt 25 by means of a nut 39 screwed to the end of the bolt. With this arrangement there is thus established an electrical connection of the front end of the heater coil I9 through the body 0f the boiler chamber I5, the wheels of the locomotive and the outer rails 3 to one end of the transformer winding 8; and another connection from the rear end 23 of the heater coil I 9, through the bolt 25, conductor 38, spring arm 36, contact shoe 31, and third rail 4 to the other end of the transformer winding B, so that when the primary winding 1 of the transformer is plugged in, electric current will flow to the heater coil I9 as long as the locomotive stands on energized rails heating the coil. The coil heats the water in which it is immersed and generates the steam which flows, as in ordinary toy steam locomotives, to the engines I2 and drives the locomotive.

By making the coil of a relatively rigid Wire in the form of a helix, no special supporting structure for the heater is required and the coil may be locked in place in a Very simple way and Without complicated and expensive structures. In manufacturing such boiler, one may proceed as follows: The boiler chamber I5, with its ends I6 and I1 ofi, has first mounted in it the insulating supporting layer 20. The heating coil I9 is prepared by having its rear end soldered to the bolt 25 which is mounted on the detached rear end I 1 of the boiler chamber. The coil with the rear end wall I1 are then mounted in place within the chamber and the edges of the end wall I1 are soldered to the cylindrical boiler section I5 so as to give a leak and pressure-proof joint. The front end 22 of the heater coil I9 is then soldered in place at 24 and the coil thus rigidly fixed in place. Thereupon, the front wall I5 is mounted over the open end of the cylindrical boiler section I5, completing the boiler. Other simple modifications will readily suggest themselves to those skilled in the art.

According to the invention, the heating coil I9 is designed with such `cross section and length as to dissipate from the coil suflicient heat and prevent its burning even if all the water in the chamber is boiled away. Depending on the various sizes of the boilers, the necessary dimensions to meet this requirement can be readily determined. In the preferred form of the invention, the coil is made of a material which has a positive resistance coefficient, so that in case the temerature of the heater wire increases due to the boiling out of the water or other reason, the resistance of the wire will increase, thereby limiting the current to a safe value at which the coil will not .reach a dangerous temperature even if all the water is gone. By this arrangement it is possible to secure fast and efcient generation of the steam and yet prevent burning out of the coil. A locomotive with such electric heater is thus perfectly safe and free from trouble, and there is no danger of frequent burning out of the heater coil and necessity 4for frequent repair. Pure nickel or pure iron are suitable for such coils, these materials having a relatively high positive resistance coefiicient.

A special feature of my invention are the means for warning the bystanders or the players that the water in the boiler fell down to an excessively low level and requires refilling for further operation. To this end the heater coil I9 is provided at the upper sides of the turns with a coating 4I of substance which emits an odorous vapor when the water boils down beyond a predetermined level. below the upper level of the coil I9, the coating 4I on the upper side of the turns becomes heated to a higher temperature than when immersed in the water. This coating is of a material which at the rise of the temperature emits an odorous gas or vapor which passes with the exhaust steam into the space surrounding the locomotive, thus giving Warning to the players or the people nearby that refilling of the locomotive is necessary.

The coating may be made of varnish by dipping the coil before assembly. The coating may also be made of any other organic covering, such as a cotton cover. Instead of coating only the upper side of the turns, the whole turns may be covered with the coating, such as an enamel, the coating materials containing a substance that emits odorous vapors when excessively heated. Substances producing such odorous vapors may also be combined with the insulating layer 29 holding the heater coil I 9 so that if the coil or the bottom f Thus, if the water boils down CFI surface of the boiler becomes excessively hot, the

substance will emit odorous vapors and give notice of the necessity to refill the boiler.'

A toy steam locomotive or engine provided with an electrical steam generating arrangement as described above will operate from any of the standard rail systems and electrical supply transformers used in connection with electrically operated locomotives and yet display the steam operation in the same way as the alcohol-heated toy steam locomotives, but entirely avoiding the disadvantages of the latter,

In order to more clearly bring out the important features of the invention, I shall give below the data about a typical toy locomotive made in accordance with the invention. The locomotive had a boiler 7 long and 1%" diameter with the usual engines and other driving equipment. To heat the boiler there was mounted therein a helical coil, as shown in Figs. 2 and 3, made of pure nickel wire .0226 inches diameter, the coil having 1A?" diameter, about 6 length, and approximately 2 ohms resistance .at room temperature. When connected to the 25 volt terminals of an ordinary 110 to 25 volts Lionel type K transformer, the coil drew about 12 amperes while immersed in the water, the current going down to less than amperes when the boiler became empty, without becoming excessively hot. Unusual results are thus obtained by using an exposed immersion heater in a boiler at the low voltage range of about 25 volts.

The invention is not limited to the details of construction and arrangements described therein, as many modifications thereof will suggest themselves to those skilled in the art, It accordingly desired that the appended claims be given a broad construction commensurate with the scope of the invention,

claim as my invention:

1. A metallic steam boiler constituting a part of a toy steam plant or the like for supplying steam to impel the same, comprising a pressuretight chamber to hold a steam generating iiuid and steam under pressure, a helical resistor coil extending through said chamber having turns adapted to be immersed in said fluid below its normal operating level and to be exposed thereto, and external electric terminal connections to the ends of said coil insulated from each other for supplying to said coil electric current to heat the coil and generate steam from the fluid, said terminal connections supporting the ends of said coil, and said coil being sufficiently rigid to stay in position and prevent conducting contact between the turns during movement of the boiler chamber.

2. A metallic steam boiler constituting a part of a toy steam loco-motive or the like for supplying steam propelling the same, comprising a pressure-proof chamber to hold a steam generating fluid and steam under pressure, an insulating barrier on the interior bottom side of said chamber, a helical resistor coil extending through said chamber over said insulating barrier having exposed turns adapted to be immersed in said fluid below its normal operating level, and a lead-in terminal connection insulatingly mounted in said chamber and connected at one end to the interior of said chamber, the other end of said coil having an insulated terminal connection through said boiler chamber to supply electric current to said coil for heating the fluid and generate steam therefrom, said coil and its terminal connections being sufficiently rigid to secure in conjimction with said insulating barrier exposure and free support of the turns of said coil and prevent short circuit between the turns and between the coil and the interior of the chamber during movement of the boiler.

3. A metallic steam boiler chamber to hold a steam generating fluid and steam under pressure, a resistor coil within said chamber adapted to be immersed in said fluid below its normal operating level, and having its coils exposed to said fluid, and external electric terminal connections to the ends of said coil for supplying thereto electric current to heat the coil and generate steam from the fluid, the length, the cross-section, and the resistance characteristics of the coil and its eX- posurewithin the chamber being proportioned to prevent temperature rise of the coil upon energization with normal voltage above a value destructive to the life of the coil in absence of fluid in the chamber.

4. A steam boiler constituting a part of a toy steam plant comprising a longitudinal metallic boiler chamber to hold a steam generating fluid and steam under pressure, a resistor coil within said chamber adapted to be immersed in said fluid below its normal operating level and having its turns exposed to said fluid, and external electric terminal connections to the ends of said coil insulated each from the other for supplying electric current to heat the coil and generate steam from the fluid, the length, the cross-section, and the resistance characteristics of the coil and its exposure within the chamber being proportioned to prevent temperature rise of the coil upon energization with normal voltage above a value destructive to the life of the coil in absence of fluid in the chamber,

5. A steam boiler for a toy steam locomotive or the like for supplying steam to propel the same, comprising a pressure proof metallic boiler chamber to hold a steam generating fluid and steam under pressure, a helical resistor coil extending through said chamber adapted to be immersed in said fluid below its normal operating level and having its turns exposed to the fluid, and terminal connections connected to the ends of said coil insulated from each other to supply to said coil electric current for heating the fluid and generate steam therefrom, said coil and its terainal connections being sufhciently rigid to secure support of the turns of said coil and prevent short circuit between the turns and between the coil and the interior of the chamber during movement of the boiler, the length, the crosssection, and resistance characteristics of the coil and its exposure within the chamber being proportioned to prevent temperature rise of the coil upon energization with normal voltage above a value destructive to the life of the coil in absence of fluid in the chamber.

6. A steam boiler for a toy steam plant comprising a pressure-proof metallic boiler chamber to hold a steam generating fluid and steam under pressure, a resistor coil within said chamber adapted to be immersed in said fluid below its normal operating level, external electric terminal connections to the ends of said coil each insulated from the other for supplying thereto electric current to heat the coil and generate steam from the fluid, and means associated with said coil for generating an odorous vapor upon excessive drop of the fluid level in said chamber.

7. A steam boiler for a toy steam locomotive or thc like for supplying steam to propel the same, comprising a metallic boiler chamber to hold a steam generating fluid and steam under pressure, a helical resistor coil extending through said chamber adapted to have its turns immersed in, and exposed to said fluid below its normal operating level, terminal connections connected to the ends of said coil and insulated from each other to supply electric current for heating the fluid and generate steam therefrom, said coil and its terminal connections being sufliciently rigid to secure support of the turns of said coil and prevent short circuit between the turns and between the coil and the interior of the chamber during movement of the locomotive, and means associated with said coil for generating an odorous vapor upon excessive drop of the fluid level in said chamber.

8. A steam boiler for a toy steam locomotive or the like for supplying steam to propel the same, comprising a metallic boiler chamber to hold a steam generating fluid and steam under pressure, a helical resistor coil extending through said chamberhaving turns adapted to be immersed in said uid below its normal operating level, terminal connections connected to the ends of said coil and insulated from each other to supply electric current for heating the fluid and generate steam therefrom, said coil and its terminal connections being sufficiently rigid. to secure support of the turns of said coil and prevent short circuit; between the turns and between the coil and the interior of the chamber during movement of the boiler, the length, the cross-section, and resistance characteristics of the coil and its exposure within the chamber being proportioned to prevent temperature rise of the coil upon energization with normal voltage above a value destructive to the life of the coil in the absence of fluid in the chamber, and means associated with said coil for generating an `odorous vapor upon excessive drop of the fluid level in said chamber,

BENJAMIN H. SMITH. 

